In image scanning and recording systems of the type having a plurality of light modulating elements in its recording unit for independently modulating incident light into a plurality of modulated light beams in response to image signals from the scanning unit to duplicate and record halftone images on a recording material, it is necessary for a light beam from a light source, such as laser, to split into a plurality of light beams and to direct them to the respective light modulating elements.
Light beam distributors of this type are known and include one disclosed in Japanese Patent Application Disclosure No. 122135/1977. The disclosed light beam distributor, as shown in FIG. 1, is in the form of a block 3 made of light transmitting material whose opposed face 1 and back 2 have parallel surfaces. The face 1 has vapor-deposited thereon a coating which reflects part of light while allowing part of it to pass therethrough. The back 2 has applied thereto a coating which provides an increased reflecting power, so that a light beam reflected on the face 1 is allowed to repetitively reflect, as shown in FIG. 1. As a result, a plurality of parallel light beams I.sub.1, I.sub.2, I.sub.3, I.sub.4, are obtained from the face 1.
The light beam distributor disclosed in said Japanese Patent Application Disclosure No. 122135/1977 operates by allowing such a plurality of light beams to fall upon a corresponding plurality of electro-optic light modulating elements, independently modulating them by said light modulating elements in response to image signals, and projecting the plurality of modulated light beams on a photosensitive material as rows of tiny light spots to successively form halftone dots, thereby duplicating and recording halftone images.
However, since the plurality of light beams from such light beam distributor are parallel light beams, if the number of split light beams is increased, it is necessary to correspondingly increase the diameter of the subsequently arranged optical system.